With the ever increasing reports of ethanol-related problems in older fuel systems, it is becoming useful to find gas stations in the area which offer ethanol-free fuel. I typically fill my cars with Chevron or Unocal 76 gasoline but Unocal is now putting nearly 10% ethynol in their mix. Chevron does not use ethanol in California but rather MTBE which will not attack older rubber hoses like ethanol will. So it's Chevron only for my cars unless I find another option in the area.
Here is a clip from the Chevron web site:
The gasoline pumps at my Chevron station say that the gasoline is oxygenated during the winter to reduce carbon monoxide emissions. What does "oxygenated" mean and why is this required?
"Oxygenated gasoline" is a mixture of conventional gasoline and one or more combustible liquids which contain oxygen ("oxygenates"). At present, the most common oxygenates are ethanol and MTBE (Methyl Tertiary Butyl Ether). The government requires gasoline to be oxygenated during the winter in areas that have a carbon monoxide pollution problem (cold weather and atmospheric inversions worsen carbon monoxide pollution). Oxygenated gasoline helps engines run leaner, which helps engines, particularly older engines, produce less carbon monoxide.
Chevron uses primarily MTBE in California and for the East-of-the-Mississippi Reformulated Gasoline (RFG) areas (see question 6 to learn more about RFG), and uses primarily ethanol for the winter oxygenated gasoline programs in Anchorage, Seattle, Spokane, Vancouver, Portland, Southern Oregon, Salt Lake City, Reno, Las Vegas, Phoenix, Tucson, Albuquerque, and El Paso.
A side bennie of using gas that does NOT use ethanol for it's oxygenate is you get better gas mileage, AND better power development. So, you literally get more bang for your buck when you use MTBE oxygenated gasolines.
Anyhoo, thought you might find this interesting...
Toyota Tests: E10 vs. MTBE for Tailpipe and Evaporative Emissions
14 March 2006
Toyota_mtbe
Summary of Toyota’s emissions findings.
Tests done by Toyota in 2000, and just published by the California Air Resources Board, show that compared to using MTBE as an oxygentate, using about a 10% blend of ethanol as an oxygenate in gasoline increases NOx tailpipe emissions and evaporative emissions in vehicles.
Toyota tested the different blends in a number of vehicles—the LS 400, Sequoia, GS 300, ES 300, 4Runner, Camry, Corolla and Echo—and found that on average the use of E10 increased NOx emissions 5.5% over MTBE, while reducing emissions of NMHC by 0.3% and CO by 6%.
MTBE (methyl tertiary-butyl ether) is a chemical compound that is manufactured by the chemical reaction of methanol and isobutylene and is used almost exclusively as a fuel additive in motor gasoline.
California banned the use of MTBE in 1999 due to the threat it posed to groundwater when underground fuel tanks leak, and switched to ethanol as an oxygenate instead. MTBE is more difficult to remove from water than other components and, in small amounts, renders drinking water unusable. Fifteen other states have also banned the additive, with others considering such measures as well.
Toyota_mtbe2
The E10 blend, in addition to producing more NOx out, proved more volatile and with higher permeation than the MTBE blend. While that makes achieving near-zero emissions “challenging”, according to Toyota, it makes achieving zero-emissions “very difficult.”
These characteristics of ethanol blends, highlighted in this assessment of lower E10 blends, add to the challenge for automakers who are seeking to develop flexible-fuel (E85) hybrids and still achieve the PZEV status—Ford being the case in point with its work on the E85 Escape Hybrid.
It would seem so, but until recently you could still find MTBE fuels. Perhaps there was a grace period to phase it out. I haven't seen a station with MTBE (or without ethanol) in many months now.
yeah... seems like maybe Jan 2007 was the cut-off ... or somewhere around there. I haven't been able to find MTBE fuel since then. Prior to that I could pull into a station, look at the pumps, and be able to tell you if they were selling E10 fuel or MTBE fuel.
At 10% alcohol you are probably still on the threshold of the gas attacking the rubber in the fuel system. If a car sits for weeks between driving there is more of a chance of rubber degeredation. The soft lines turn hard as a brick after prolonged exposure.
Use SAE rated J30R9 fuel line hose where there is soft lines which has more resistance to alcohol. J30R7 is also acceptable but not as good as the 9.
Not much you can do about carb diaframs etc where no upgrade is possible.
I mean it's not the end of the world and you dont have to run right out and change things......just keep an eye out.
